Environmental allergenic disease is a major cause of illness and disability in the US, and there is broad consensus that the prevalence of type I allergy is increasing worldwide. In spite of the substantial societal and health costs, the methods used to detect and quantify allergens in environmental health studies limit measurement to a few well characterized allergens that represent less than 10% of total allergen diversity. Recent advances in biotechnology have yielded potentially useful functional binding biomolecules (aptamers) that can enable low cost, high affinity allergen measurement. Aptamers are selected in vitro from combinatorial oligonucleotide libraries and therefore have several advantages over the traditionally used antibodies for detection of allergens. Among these advantages are higher stability, binding affinities greater than or equal to monoclonal antibodies, a dramatic decrease in production and assay cost, and the ability to target specific IgE binding epitopes of an allergenic protein. The overall goal of this research is to determine the feasibility of using aptamer-based methods for measuring environmental allergens. Two core development issues must be addressed to achieve this goal, and they form the basis for the first two specific aims. First, aptamers that are specific for the whole allergenic protein and aptamers that are specific for an IgE epitope binding peptide within the allergen will be produced via the SELEX method and their binding affinities characterized. Alternaria mold (Alt a 1) and dust mite (Der p 1) allergens will be targeted. Next, the aptamers will be tested in an inhibition type assay to determine cross reactivity, limits of detection, and the ability to mimic IgE epitope binding. Integrating the resulting aptamer-based allergen measurements to enhance quantitation in an ongoing and complementary environmental childhood asthma epidemiological study forms the basis for the third and final aim. Correlations between allergen specific IgE blood levels and environmental level of these allergens measured by antibody-based, aptamer-based, and specific IgE-based methods will be produced. Successful use of aptamers for measuring environmental allergens should lead to a more cost effective, flexible, and health relevant method and thereby provides the potential for a more fundamental understanding of the role of environmental allergens in respiratory health. [unreadable] Allergenic disease is a major cause of illness and disability in the US. In spite of the substantial health and monetary costs, the methods used to study allergens in the environment are underdeveloped. The purpose of this research is to test the feasibility of a more flexible and low cost allergen measurement method (aptamers). The successful application of this aptamer technique should lead to a more cost effective and health relevant allergen detection method and enable a better understanding of disease caused by and exacerbated by environmental allergens. [unreadable] [unreadable] [unreadable]